硅和二氧化硅对铁水脱磷的影响差异

Effect differences of silicon and silicon dioxide on hot-metal dephosphorization

为了解硅和SiO_(2)的含量对脱磷的影响差异,基于Fe_(2)O_(3)-CaO-SiO_(2)-CaCl_(2)渣系在1400℃的脱磷效果,分别以硅铁和SiO_(2)作为铁水和脱磷剂的添加物,进行含磷0.3%(质量分数)铁水的脱磷试验.同时,为进一步了解两种组分在脱磷过程中的影响差异,分别以等摩尔量的硅和SiO_(2)作为铁水和脱磷剂的初始组分,进行不同时间的铁水取样试验.结果表明:随着等摩尔量的铁水初始硅含量[Si]_(i)和脱磷剂初始SiO_(2)含量(SiO_(2))_(i)的增加,硅组试验中的铁水终点磷含量[P]_(f)快速下降,而SiO_(2)组试验中的(SiO_(2))_(i)对[P]_(f)的影响并不明显.两组试验所得终渣内P_(2)O_(5)活度系数γ_(P_(2)O_(5))均下降,但硅组试验中的γ_(P_(2)O_(5))始终高于SiO_(2)组试验中的γ_(P_(2)O_(5)).此外,当[Si]_(i)和(SiO_(2))_(i)摩尔量相等时,它们对脱磷过程的影响差异集中在脱磷初期和中期,后期二者的脱磷特征则较为接近.

To understand the effect differences of silicon and SiO_(2)content on dephosphorization,based on the effect of Fe_(2)O_(3)-CaO-SiO_(2)-CaCl_(2)slags at 1400℃,dephosphorization experiments were carried out on P(0.3%,mass fraction)-containing hot metal with ferrosilicon and SiO_(2)as additives in hot metal and dephosphorizer.Meanwhile,to further understand the effect differences of the two components on the dephosphorization process,hot-metal sampling experiments at different times were carried out with equimolar silicon and SiO_(2)as the initial components of hot metal and dephosphorizer,respectively.The results show that with the increase in equimolar initial hot-metal silicon content[Si]_(i)and initial dephosphorizer SiO_(2)content(SiO_(2))i,the final hot-metal phosphorus content[P_(f)in silicon group experiment decreases rapidly,while the effect of(SiO_(2))i in the SiO_(2)group experiment on[P_(f)is not obvious.Activity coefficientsγP_(2)O_(5)of P_(2)O_(5)in final slag obtained from the two groups of experiments decrease,butγP_(2)O_(5)in the silicon group experiment is always higher than that in the SiO_(2)group experiment.In addition,when the molar amounts of[Si]_(i)and(SiO_(2))i are equal,their effect differences on the dephosphorization process are concentrated in the early and middle stage of dephosphorization,and the characteristics in the later stage are relatively similar.